(a) Field of the invention
The present invention relates to a process for producing alkyl adamantanes.
According to the present invention, alkyl adamantanes can be produced efficiently from tetracyclododecanes which is prepared by using such petrochemical materials as dicyclopentadiene.
(B) Description of the prior art
Heretofore, upon producing tricyclic adamantane skeleton, method comprising hydrogenation of such tricyclic compounds as acenaphthene, fluorene, anthracene, phenanthrene etc. and then isomerization of them have been widely used. For example, in order to obtain 1,3-dimethyl adamantane perhydroacenaphthene which is prepared by complete hydrogenation of acenaphthene has been employed. However, in this method, costs become high, for the starting material, acenaphthene, is prepared by distillation of coal tar and thus its supply is very limited in quantity. Moreover, complete hydrogenation of acenaphthene required very drastic condition which causes many difficulties in actual operation.
Recently, a method of producing alkyl adamantane (C.sub.12 H.sub.20) by using tetracyclic compound as starting material in the presence of AlBr.sub.3 or a sludge of AlBr.sub.3 has been reported, but its reaction yield is very low and this method is not satisfactory for practical application.